II. Acid haematin method using a haemoglobinometer (Sahli�s method)
In the course of a study of the blood in the anemias of infancy, certain discrepancies were encountered in the acid hematin method of determination of hemoglobin described by Sahli.The study of the cause of these discrepancies has led to a modification of the method to produce accurate determinations comparable with those obtainable when a determination of hemoglobin by measuring its iron content, or by the carbon monoxide hemoglobin method, is made. These modifications consist in: first, the use of N/10 hydrochloric acid as the diluent of the acid hematin instead of water; and second, the employment of heat to bring the reaction of formation of the acid hematin to its endpoint of equilibrium more quickly than it occurs in the cold.
Since the introduction of the acid hematin method by Sahli, various criticisms of it have been made. From the mechanical side these have been well summed up

 instument
1.haenoglobinometter
2.hemoglobin matching box 
3.hemoglobin tube
4.glass rod
5.alcohol  pad
6.N/10 HCL
7.leancet
  
Procedure